(a) Technical Field
The present disclosure relates to a liquid crystal display.
(b) Discussion of Related Art
Liquid crystal displays (LCDs) are one of the most widely used flat panel displays. Typically, an LCD includes a pair of panels provided with field-generating electrodes, such as pixel electrodes, and a common electrode, with a liquid crystal (LC) layer interposed between the two panels. The LCD displays images by applying voltages to the field-generating electrodes to generate an electric field in the LC layer that determines the orientations of LC molecules therein to adjust polarization of incident light.
Among such LCDs, there is a vertical alignment (VA) mode LCD, which aligns LC molecules such that their long axes are perpendicular to the panels in the absence of an electric field. The VA mode LCD is favored because of its high contrast ratio and wide reference viewing angle.
In the vertical alignment (VA) mode LCD, the wide reference viewing angle can be realized by forming a plurality of domains including the liquid crystal molecules that have different alignment directions in one pixel.
To form the plurality of domains in one pixel one method involves forming minute cutouts in the field generating electrodes, and another method involves forming protrusions on the field generating electrodes. In this way, the plurality of domains may be formed by aligning the liquid crystal molecules vertically with respect to a fringe field generated between the edges of the cutout or the protrusions and the field generating electrodes facing the edges.
As another approach for forming the plurality of domains in one pixel, there is a light alignment method in which the alignment direction of the liquid crystal molecules and the alignment angle are controlled by irradiating light on the alignment layer.
As a drawback, however, the liquid crystal display of the vertical alignment (VA) mode has lower side visibility compared with front visibility, and it is proposed that one pixel be divided into two subpixels and different voltages applied to the subpixels to solve this problem.
Among the various methods for achieving the above-mentioned solution, one data voltage is applied to two subpixels, and then the charged voltage of one subpixel is decreased and the charged voltage of the other subpixel is increased through a voltage boosting capacitor such that the visibility may be improved by differentiating the voltages of the two subpixels without reduction of the aperture ratio due to an increase of the number of data lines or gate lines. Also, there is no need to make the two subpixels capacitively coupled to each other, which may decrease the luminance.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.